Front locker light on

[SkinnyFat]

We had a leak in the front of our 1989 Syncro and I thought it was coming from the front diff. I took it to my mechanic, the best in the area and he pinpointed the front diff locking actuator shaft seal was leaking.

The seal was replaced so I dropped and wife went to pick the van up. Its her van and she has missed it plus I was mask-less. She noticed the front diff light was on immediately which to me would been a stop and ask the shop but she drove off.

To make a long story short the diff is definitely not engaged but the light remains on. Anybody have this happen? Any clues to help trouble shoot it?

[4Gears4Tires]

What happens when you engage the front diff? I would look at the connector and give it a good jiggle.
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'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[MarkWard]

What happens when you unplug the switch at the front differential? If the light goes out, you have a problem at that end.

[SkinnyFat]

Alright a little more info. Locker knob seems jammed will not move and light is beaming. Worried I should not even drive it. Worst thing would seem on the highway cruising at 65 and the front just says now I'm not kidding and front decides to engage.

I feel like somebody screwed with this at the shop....

[MarkWard]

The switch is a vacuum valve. There is no mechanical connection between it, the light, and the locker servo. So if the switch is jamming, it’s not related to the light or the seal that was replaced.

Rather than blaming the shop, I’d reach out to them and explain the symptoms. I gave you a suggestion how to pinpoint where the light illuminating problem is. The shop can tell you how to proceed.

[SkinnyFat]

Thank you for your advice, it is what I am doing.

I guess it has hard for me to understand some of the mechanics in the system as I should. It seemed easy to blame the shop as the knob worked fine before it was dropped off and the seal was replaced. It just seems bizarre it now is inop. Don't they have to disconnect those components you mention?

This shops owner is absolutely the best most well healed in the area. Plus he is super nice and been working on Van's forever.

[MarkWard]

Prior to going to the shop? When was the last time you used the front locker? There are not many conditions that you would lock the front.

The actual part that engages the locker is a vacuum motor/servo bolted to the housing. Vacuum is stored from the engine system in a reservoir under the van. When you pull the knob, vacuum is routed to the inner nipple of the vacuum motor and the locker shaft moves in engaging the differential lock. There is a simple mechanical switch on the case, that is depressed as the shaft moves in to lock, turning the indicator light on.

When you push the knob in, vacuum at the switch is reversed and the vacuum motor pulls the locker out of engagement and the switch turns the light off.

If the light is illuminated, something is holding the switch on most likely. It could be as simple as the wrong thickness crush washer. Thats why unplugging the switch would be the first step to diagnosing.

[vw4wd]

If I remember correctly, to replace the seal on the lock operating shaft, you have to fairly well dismantle the diff. Including removing the shaft and therefore the switch. There should be an aluminium spacer/washer under the light switch in the diff. Has that gone missing?

Disconnect switch wiring, unscrew switch a couple of turns and reconnect. Has the light gone out now?
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Garyd

1990 Transporter syncro camper with 2 litre AGG 'GTi' engine

[SkinnyFat]

Thank you all for the great pointers. My girl and I are getting lost in the woods for a week so the van is going to sit under shelter for a bit and then get remedied.

Bottom line I feel is the the van was dropped off to replace the seal with no light on and an operating knob. Now the light is on and the knob is jammed (not op cannot pull out). As vw4 noted the entire driver side of the axle and diff was dismantled including the switch connection for the seal replacement.

Initially I thought the light was the only thing but the whole front knob system is not op. It sure seems clear to me something was not reassembled correctly or something broke in the reassembly.

I have not used this forum for awhile.... been working on a remodel and like a dog at work. But everytime I do I am amazed at help/advice you all give to a fellow VW enthusiast. Thank you all and I'll keep the thread alive to post the out come in the weeks ahead.

SF

[vw4wd]

On the stuck front locker control knob. As has been said, there is nothing in the system that can remotely prevent this movement. Did it definitely operate before the van went into the shop? There is no reason for them to have dismantled the control panel just to do the seal.

Also, have you remembered that the knob needs to be rotated a short way, against a spring, before it can be pulled out? (stage one safety measure - tells your hand you're on the front locker not the rear. Stage two is the flashing light telling you the lock is trying to engage when it will dramatically affect your ability to steer!)

If the panel was dismantled it is possible to get the back of the knob the wrong side of the spring 'stop' and this will prevent the rotation.
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Garyd

1990 Transporter syncro camper with 2 litre AGG 'GTi' engine

[SkinnyFat]

I did not know that and now feel like a moron. It is so rare to need the front wth back picked. Thought each one just pulls out. Ok I get the nimrod award this week. Hopefully it is just the switch and the knob/diff is functioning.

[vw4wd]

Don't feel bad. Everyone has to these things somewhere along the way.

Note that there have been over 130 views of your topic and no-one else has picked up on this so you're probably not the only one who hasn't appreciated this point.

Hopefully, the shop has the ali spacer washer 'left over' and can quickly install it for you.
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Garyd

1990 Transporter syncro camper with 2 litre AGG 'GTi' engine